Why the scale system matters
The scale system does two jobs. It decides which scale presets the scale list offers, and it decides how every length and area is displayed: metres and square metres, or feet, inches and square feet. UK and European drawings are almost always metric; North American drawings are usually architectural. Pick the system that matches the drawing's title block before you set the scale.
Where the control is
The scale system select is in the header of the takeoff workspace, between the paper size pill and the scale select: Metric. It has three options: Metric, Architectural and Both.
The choice is saved with the drawing, so every drawing in a project can use a different system.
What each system offers
| System | Presets in the scale list | Default scale | Measurements display as |
|---|---|---|---|
| Metric | Metric ratios (1 : 200 down to 1 : 1), None, Custom | 1 : 100 | Metres and m² (3.76 m, 115.24 m²) |
| Architectural | Imperial ratios (3' = 1' down to 1/128" = 1'), None | 1/4" = 1' | Feet and inches, and ft² (12' 4", 1076.39 ft²) |
| Both | Both lists, grouped under Metric and Architectural headings, plus None and Custom | 1 : 100 | Metres and m² |
Two details catch people out:
- Both always displays metres. It merges the two preset lists so you can pick an imperial ratio, but a measurement made under Both still reads in metres, never in feet.
- Architectural has no Custom entry. To type a ratio or calibrate against a scale bar you need Metric or Both. See Calibrating a Drawing.
Under Architectural, lengths are rounded to the nearest inch before display, so a badge reads 8" for anything under a foot and 12' 4" above it. Pipe diameters such as Ø22mm are component sizes rather than measurements and stay in millimetres in every system.
Changing the system on a drawing
- 1
Open the drawing you want to change.
- 2
In the header, click the scale system select Metric.
- 3
Choose Metric, Architectural or Both.
- 4
If the drawing already has Linear or Area groups, answer the Update Existing Groups? prompt (see below).
The scale select immediately resets to the new system's default (1 : 100 for Metric and Both, 1/4" = 1' for Architectural), so check it and pick the right preset next. See Setting the Drawing Scale.
The "Update Existing Groups?" prompt
When you change the system on a drawing that already has Linear or Area groups, ZeroCount asks:
Update Existing Groups?
Scale system changed to Architectural. Would you like to update all existing Linear and Area groups to the new default scale?
The message names Metric when you switch to Metric or to Both.
- Yes, Update All — every Linear and Area group is set to the new system's default scale, and their lengths and areas are recalculated.
- No, Keep Existing — the groups keep the scale they were drawn at. Only new groups use the new default.
Choose Yes, Update All when the drawing was measured under the wrong system. Choose No, Keep Existing when the existing groups were right and you only want the display units to change.
Switching system is not a units conversion for existing groups. Under Yes, Update All a group drawn at 1 : 50 is re-scaled to the new default (for example 1/4" = 1', which is 1:48), not to the imperial equivalent of 1:50. If the groups need a specific scale, change it afterwards with Adjust Scale.
Setting your default for new drawings
New drawings start in the system chosen in your preferences:
- 1
Open the user menu at the bottom of the sidebar and click User Preferences .
- 2
Select the Measurement tab .
- 3
In the Units & Scale card, set Default Scale System to Metric, Architectural or Both.
- 4
Click Close.
Changing this preference also switches the drawing you currently have open. Drawings you have already worked on keep the system saved with them.
Common issues
Measurements show metres even though I picked an imperial preset
You are in Both. Switch the system to Architectural to see feet and inches. When prompted, choose No, Keep Existing if the groups were drawn at the right ratio.
The badges on the drawing look wrong straight after switching
Immediately after Yes, Update All, the badges on the drawing can briefly show the new unit against the old figure. The sidebar values are correct; the badges catch up on the next repaint.
Next steps
- Setting the Drawing Scale — pick a preset or type a ratio once the system is right.
- Calibrating a Drawing — work the scale out from a scale bar or dimension.
- Showing Measurements on the Drawing — what the badges look like in each system.
- Exporting to Excel — how the export writes feet and metres.
- User Preferences — every setting in the Preferences dialog.